The news that Google harbors profound reservations about the growth of Samsung, as an Android platform user and smartphone leader, came as a surprise, but in the world of smartphone economics all partners are potential rivals, as Google well knows from Eric Schmidt's time on the Apple board.

Google executives worry that Samsung has become so big—the South Korean company sells about 40% of the gadgets that use Google's Android software—that it could flex its muscle to renegotiate their arrangement and eat into Google's lucrative mobile-ad business, according to the WSJ.

What's the worry? Google's glorious future could be compromised by the ultra low-cost phone movement that Nokia and Mozilla are competing over - adding the next billion or so users. But it could also be worried by Samsung's own ad network development and Samsung's background pursuit of it own OS for smartphones, Tizen.